Amtrak’s Downeaster service will be interrupted this Saturday and Sunday because crews in Massachusetts will be doing extensive track work on the section between Boston and Haverhill, Mass.

On both days, there will be no train service between Boston and Haverhill. For southbound trains, Haverhill will be the last stop.

The Northern New England Passenger Rail Authority, which operates the service, has dropped its one-way fares for the weekend to $10 for adults, $5 for children between any station from Haverhill to Brunswick.

Buses may be available between Boston and some stations, including Saco, said Patricia Quinn, the rail authority’s executive director.

To determine if a bus is available, she said, people should make a reservation at

Quinn said the service will experience a similar interruptions on May 17 and May 18.